Open AccessUltrastructural changes and kinetic relationships of the secondary nucleolus and nuclear bodies in previtellogenic oocytes of the dragonfly Cordulia aenea
Author(s) -
HALKKA LIISA
Publication year - 1981
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/j.1601-5223.1981.tb01416.x
Subject(s) - nucleoplasm , nucleolus , biology , ultrastructure , nucleus , microbiology and biotechnology , cell nucleus , biophysics , anatomy
Previtellogenic oocytes of the dragonfly Cordulia aenea were studied before, during and after diapause by means of cytochemical, histochemical, electron microscopical and cinemicrographical methods. The secondary nucleolus (SN) consisted of a loose basic protein matrix into which sparse RNP grains were embedded. The proteinaceous matrix of SN was mobilized in postdiapause oocytes passing to late previtellogenesis. The possible role of SN in production and storage of oogenetic 5S RNA is discussed. A granular nuclear body (GNB), often associated with SN, is believed to be the source of RNP granules of SN. A dotted nuclear body (DNB) was found either free in the nucleoplasm or intimately connected with the SN. DNB probably represents a transport vehicle of SN material. In cinemicrographs, a nuclear body was found moving free in nucleus or rolling or knocking on the surface of SN.